Optical communication systems often rely on laser diodes to transmit optical signals into the fibers. Lasers are nonlinear devices and their optical output is often heavily distorted even if they are driven by a fast and smooth electrical waveform. A major challenge for DML (direct modulated laser) drivers is the non-linear behavior of the laser. In response to an input signal, the laser outputs a pulse or a signal rising from a logic level zero to a logic level one or the like. This creates an optical signal with a rising edge and a falling edge. In some embodiments, the optical falling edge of the optical signal is much slower than the rising edge of the optical signal, and moreover the rising edge of the optical signal usually shows ringing behavior due to relaxation oscillation. Such a non-linear behavior degrades eye pattern quality, eye pattern margin and therefore the overall transmission quality. This results in limited data rates or increased bit error rates. It is known that use of signal shaping circuits can help to mitigate those nonlinear effects.
However, signal shaping circuits are usually very power consuming because a differential topology may be implemented and power is needed merely for biasing the structure of the signal shaping circuits. The present disclosure presents a method and a system that solve this technical problem, for example, to implement a low power signal shaping circuit to mitigate nonlinear effects of lasers.